河北西北部熔积岩特征及其地质意义  

Characteristics and geological significance of peperite in northwestern Hebei Province

作　　者：白志达[1] 徐德斌[1] 孙善平[1] 

机构地区：[1]中国地质大学,北京100083

出　　处：《岩石矿物学杂志》2006年第6期487-492,共6页Acta Petrologica et Mineralogica

基　　金：国土资源部地质大调查资助项目(199613000032)

摘　　要：熔积岩是火山碎屑岩的一种特殊类型,由熔浆和未固结的湿沉积物两种组分掺杂混合而成。熔积岩的形成主要受炽热熔浆与未固结的湿沉积物接触时引起的淬碎或蒸汽爆炸作用以及寄主沉积物流体化作用控制,通常分布于熔岩流底部或前缘,也可分布于超浅成侵入体周围。据熔浆碎屑物的结构特征,冀西北熔积岩可分为流状和块状两种类型。流状熔积岩多是熔浆与细粒沉积物混合的结果,块状熔积岩大多与粗粒沉积物相关。正确鉴别熔积岩对确定沉积作用与岩浆作用的时序、研究盆地发展演化历史具有重要意义。Peperite is a special kind of volcaniclastic rock formed by the intermingling of magma with wet sediments. The formation of peperite is mainly controlled by the fuel-coolant interactions （FCI） or phreatomagmatism and the fluidization of the host sediments. Peperite usually occurs at the bottom and the frontal part of the lava flows and is also distributed around shallow intrusions. Based on the textures, the authors classified peperite in northwestern Hebei into two types, i.e., fluidal and blocky. The fluldal peperite is produced by the mingling of magma with fine sediments, while the blocky peperite is related to coarse sediments. Correct identification of the peperite is important in studying the chronology of magmatism and the evolution of basins.

关 键 词：熔浆 未固结沉积物 混合 熔积岩 冀西北 

分 类 号：P588.211[天文地球—岩石学]